1. Field of the Invention
The present invention relates to an ink, an inkjet printer, and a method for printing.
2. Discussion of the Background
Solvent inks and UV (ultraviolet) curable inks are examples of inks that are typically used in inkjet printers. The solvent ink is primarily an ink in which a pigment and a binder resin are dispersed in a volatile solvent. The ink is sprayed from an inkjet head on the surface of a medium (printing medium), and then the volatile solvent in the ink is volatilized by using a heater that is arranged beneath the printing medium. Consequently, the ink is fixed on the surface of the printing medium leading to printing of an image.
On the other hand, the UV (ultraviolet) curable ink contains a pigment, an ultraviolet curable resin (monomer or/and oligomer), polymerization initiator, etc. The UV ink is sprayed from the inkjet head on the printing medium, and then an ultraviolet light is irradiated by using an ultraviolet irradiation unit to cure the resin. Consequently, the ink is fixed on the surface of the printing medium leading to printing of an image.
The solvent ink is advantages in that, because the viscosity of the ink is low the ink spreads thinly on the surface of the medium and the surface of the ink is also flat, high-quality glossiness is obtained in the printed image. However, there are disadvantages that because the volatile organic solvent content is higher than 80 wt % (percent by weight), the ink runs the moment it is deposited on the printing medium, and therefore, a fine image cannot be produced. Furthermore, it is necessary to use vinyl chloride, rubber, or a special paper as a printing medium so that the choice of the material of the printing medium is limited.
The applicant has disclosed a technique for preventing running of the ink in International Publication No. 2004/094150. The inkjet printer disclosed in International Publication No. 2004/094150 includes a pre-heater that preheats a supporting body, and a heater that quickly heats the ink deposited on a platen (recording medium) arranged on the supporting body.